1. Field of the Invention: The invention relates to phenol-aldehyde foams.
2. Description of the Prior Art: Phenolic foam compositions are described in U.S. Pat. No. 3,389,094 which discloses the general composition of such materials including a phenol-aldehyde resol, a condensation catalyst, a cell control agent and a haloalkane blowing agent. The patent also discloses the use of epoxy resins as additives for altering the properties of the resulting foams.
Other resinous materials have been added to phenol-aldehyde foam formulations for various purposes. For example, copolymers of fumaric acid diesters and vinyl aromatics (U.S. Pat. No. 3,862,912); acrylic esters, polyvinyl acetate, polyvinyl chloride (German application No. 1,769,927); unsaturated polyester resins or monomers (Canada Pat. No. 674,181); alkylene oxide adducts of phenol (U.S. Pat. No. 3,741,920); polyallyl compounds (U.K. Pat. No. 758,562); polyvinyl acetate; alcohol or acetal, e.g. polyvinyl butyral (U.K. 965,218); ethoxylated castor oil (U.S. Pat. No. 3,779,959) and certain thermosetting resins such as polyvinylals (U.S. Pat. No. 2,933,461).